BMI is not used to definitively diagnose obesity – as people who are very muscular sometimes have a high BMI, without excess fat – but for most people, it can be a useful indication of whether they may be overweight.

A better measure of excess fat is waist circumference, and can be used as an additional measure in people who are overweight (with a BMI of 25 to 29.9) or moderately obese (with a BMI of 30 to 34.9).

Generally, men with a waist circumference of 94cm or more and women with a waist circumference of 80cm or more are more likely to develop obesity-related health problems.

Causes of obesity

Obesity is generally caused by consuming more calories – particularly those in fatty and sugary foods – than you burn off through physical activity. The excess energy is then stored by the body as fat.

Obesity is an increasingly common problem, because many modern lifestyles often promote eating excessive amounts of cheap, high-calorie food and spending a lot of time sitting at desks, on sofas or in cars.

There are also some underlying health conditions that can occasionally contribute to weight gain, such as an underactive thyroid gland (hypothyroidism), although conditions such as this don’t usually cause weight problems if they are effectively controlled with medication.

Treating obesity

The best way to treat obesity is to eat a healthy, reduced-calorie diet and to exercise regularly. To do this you should:

eat a balanced, calorie-controlled diet as recommended by your GP or weight loss management health professional (such as a dietitian)

join a local weight loss group

take up activities such as fast walking, jogging, swimming or tennis for 150-300 minutes a week

eat slowly and avoid situations where you know you could be tempted to overeat

You may also benefit from psychological support from a trained healthcare professional, to help change the way you think about food and eating.

If lifestyle changes alone don't help you lose weight, a medication called orlistat may be recommended. If taken correctly, this medication works by reducing the amount of the fat you absorb during digestion. Your GP will know whether orlistat is suitable for you.

Outlook

There is no "quick fix" for obesity. Weight loss programmes take time and commitment, but they work best when people are able to complete the programmes fully and are offered advice about maintaining the weight loss achieved.

Regularly monitoring your weight, setting realistic goals and involving your friends and family with your attempts to lose weight can also help.

Remember that even losing what seems like a small amount of weight (such as 3% or more of your original body weight), and maintaining this for life, can significantly reduce your risk of obesity-related complications like diabetes and heart disease.

Losing weight: how your GP can help

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A GP talks about visiting your doctor to get help with losing weight. He describes how you'll be assessed and given an individually tailored weight loss plan. Elinor, who had health problems caused by her weight, explains why she asked her GP for help instead of choosing to follow a commercial diet.

Media last reviewed: 30/04/2013

Next review due: 30/04/2015

Couch to 5K

If it's been a long since you did any exercise, you should check out the NHS Choices Couch to 5K running plan.

It's made up of podcasts delivered over the course of nine weeks and has been specifically designed for absolute beginners.

You first start running for short periods of time and as the plan progresses, gradually increase the amount.

When the nine weeks ends, you should be able to run for 30 minutes non-stop, which for most people is around five kilometres.

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Comments

The 9 comments about ‘Obesity’ posted are personal views. Any information they give has not been checked and may not be accurate.

evo25uk said on 20 March 2014

I had always been thin until I moved in with my partner. Since then I have put on 5 stone! As I stopped smoking at the beginning of this year, losing weight is not the priority it might otherwise be for my doctor. Since I stopped smoking I have also suffered from breathlessness. Not when I exercise but when I am walking around my flat. This has now been accompanied with dizziness thatais almost constant. I'm not sure if this is related to my weigh but it does affect my day to day activities. When exercising, which I am doing daily, I have a breathing pattern you would expect, slightly quicker but nothing of concern yet walking from one room to another leaves me struggling for breathe, so I am umsure whether the weight gain has caused my breathlessness. I too suffer from depression and have recently changed medication. The result from this has done me wonders. I have my motivation to lose weight back and am looking forward to returning to work. I know that losing weight is my responsibility and am looking forward to feeling comfortable with myself again.I can only thank my doctors for their determination to make me feel more positive about life.

CEJ135 said on 11 March 2014

I think doctors need to realise that obesity isn't just about eating badly and not exercising, they need to look into the mental health of the obese people. I am morbidly obese and, even though I know all the risks to my health, I continue overeating because my depression makes me have no motivation to do anything about it and it boosts my mood (albeit temporarily). I know all about healthy eating, I know the foods and portion sizes I should be having. I just don't do it. Not through choice but because my own mind stops me.

Ondat said on 25 February 2014

I think there's some useful, practical information on this site. But for people like me, knowledge wasn't the issue. i used food and overeating to cope with life, without really even realising I was doing it, while having an almost encyclopaedic knowledge of everything food, weight and health- related.

The more I overate and the larger I became, the larger I became, the more I struggled with low self esteem and the more I ate. I would constantly plan to lose the weight in the belief that this would be the key to happiness, but when I was successful at losing weight and still wasn't happy, I'd sabotage myself and overeat again. I went on eating binges, and was so ashamed of my behaviour that most of my eating was in secret.

I think that overeating for some people is a compulsion over which we have, despite years of trying, no control. I see overeating or using food as similar to using alcohol for an alcoholic or drugs for an addict.

When I finally admitted to myself that my problem was food, I was lucky enough to find a self help group called Overeaters Anonymous (OA). In the same way that Alcoholics Anonymous helps alcoholics stop using alcohol, in OA we support eachother to tackle our food problems. It's not a diet and calories club and won't tell you what to eat. There are meetings in most cities and they have a GB website if you want to find out more.

Without being on a diet, I've lost a lot of weight in OA, but have gained so much more than that - a programme that helps me live life sanely and happily without turning to excess food for comfort. My head is no longer obsessed with eating, diets, bdoy image. It's a relief to be with so many others who've suffered alone for many years. Anyone with a desire to stop eating compulsively is welcome at any meeting.

hhmmmmm said on 05 February 2014

Incredibly out of date information that will not help people much

I would argue can your doctor help you? The evidence suggests not because we are still overweight and they prescribe calorie controlled diets with more exercise ignoring the dozens of studies showing those diets don't work. And why would they? Reducing calories on the recommended diets make people hungry and miserable and exercising makes people even hungrier and the body compensates by slowing down metabolism.

If calorie controlled diets fail to work over the long term (the figures from meta analysis of diet studies over the past 15 show about 2% of people have long term significant weight loss on calorie restricted diets over the course of at least 18 months or 2 years they have no significant loss, often they will gain weight.

If you start to realise the clinically proven to work diets see and target excessive consumption of refined carbohydrate and sugar, then you see a problem you can do something about it by managing that. It causes both excessive consumption of calories and chronically high insulin levels which drive fat storage (and a number of other problems).

Try paleo (which has worked wonders for me) with a focus on non-starchy vegetable and meat, fish, poultry and eggs or low-moderate carb diet such as The Zone diet or even a ketogenic diet which have consistently shown in many numerous long and short term diet studies to be both more effective at long term weight loss and better at reducing risk factors for heart disease and diabetes than low calorie and particularly low fat diets and the long term success rates of these diets are 1 in 2, not 1 in 50 as is the case with the diets most (not all) doctors prescribe and as written out here.

If 1 in 50 was the success rate for other medical treatment, we'd be questioning the sanity of it.

It is also worth mentioning these were often the diets prescribed to lose weight by doctors before the 60s/70s.

izzy33 said on 21 July 2013

8 weeks ago i had a bmi of 28.8 and 32% body fat - so not obese but certainly overweight - i got weighed today and i now have a bmi of 27.3 and 17.7% body fat. I've lost around 2 stone in fat and gained around 1 stone in muscle mass. This has been through the paleo diet and lots of exercise (walking, local gym membership, cycling). i recommend these steps as they certainly worked for me (although of course this diet won't work for everyone, and you shouldn't try to run before you can walk!) - i am also a great believer in having a positive, can-do attitude - go on - you can do it!!

Rache1972 said on 18 January 2013

I agree silva82. I myself have recently been diagnosed with pcos and have lost over 8 stone by going to a slimming club. However I cannot get any further treatment until I lose more weight, to which I asked how much and how as now I haven't lost any weight since March 2012, the answer just keep trying!

silva82 said on 26 July 2012

Its all well and good to explain what obesity is, how many people are obese in uk and what damage obesity does to us!

But what actual physical and emotional support does the nhs actually offer?

Does being referred to a dietician really help? iv been there! And no it did nothing for me, I would like to think that most people in 2012 will know what foods to eat and what not to eat!

I have pcos and have suffered from obesity all my life and not once have I been given any help from my gp!

I have had to deal with periods lasting 6 months embarrassing facial hair and being obese and the best advice my gp was able to give me was "oh dear you have to lose weight and come back in a few months to check progress" well thanks ! tell me something I didn’t know!

NHS say there is a huge obesity problem, here’s an idea....... actually do something to help obese people!

a country like the uk should have weekly support both physical and emotional, access to exercise classes for free (or even based on a small donation by the obese person) in every hospital.

andyjones1247 said on 14 June 2012

I was obese at 22st in jan 2012 and I reduced my food consumption and added excercises daily and now 6 months on I am down to 17st it's all about will power and all these excuses I.e. " I have a slow metabolism", " I don't eat a lot", etc etc are all just excuses ( yes I've used them all ) but now I realise it's me and only me that can change " yes you guessed it me" so come on people dedication and not giving up, changes don't come overnight but they will come of you stick with it and don't give up!